Vertebrate animals feature a flexible, bony skeletal framework that provides the body shape, protects vital organs, and enables the body to move. The human skeleton comprises approximately 206 separate bones. These bones meet at joints, the majority of which are freely movable. The skeleton also contains cartilage for elasticity, and muscular ligaments consisting of strong strips of fibrous connective tissue for holding the bones together at their joints.
The femur, fibula, tibia, and metatarsal bones of the legs and feet support the body and therefore bear its weight. Muscles associated with the ilium, pubis, ischium, patella, tarsal, and phalanges bones provide the necessary bending of the hips, knees, ankles, and toes that are essential for humans to walk, run, climb, and engage in other locomotion activities.
Likewise, the humerus, ulna and radius bones and metacarpal and phalanges bones form the arms and hands, respectively. Muscles associated with the clavicle, scapula, and carpals enable the arm to bend or flex at the shoulder or elbow, and the hand to flex at the wrist and fingers, which is useful for lifting, carrying, and manipulating objects.
Over time, body bones or joints can become damaged. Bones fracture; ligaments tear; cartilage deteriorates. Such damage may result from the aging process, manifested by arthritis, osteoporosis, and slips and falls. But injuries are also caused by sports activities. For example, recreational and competitive running is enjoyed by some 37 million Americans with 25% of them suffering from running injuries annually. Meanwhile, 57 million Americans bicycle for recreational or transportation purposes. In addition to bodily injuries caused by falls, prolonged bicycling can result in groin discomfort or numbness. This medical injury is caused by the horn of the bicycle saddle creating pressure points that can occlude the arteries and veins that supply blood flow to the genitals. Within the 1999-2004 time period, 21 publications within multiple medical specialties (e.g., sexual medicine, urology, neurology, cardiology, biomedical engineering, sports medicine and emergency medicine) established a clear relationship between bicycle riding and erectile dysfunction (“ED”).
A number of different approaches have been taken within the industry and the medical community for preventing or treating these injuries. Exoskeletons entail external support systems made from strong materials like metal or plastic composite fibers shaped for supporting proper posture of the human body. Honda Motor Co. has employed “walking assist devices” for its automotive factory workers to support bodyweight for reducing the load on assembly line workers' legs while they walk, move up and down stairs, and engage a semi-crouching position throughout a work shift. The U.S. military has experimented with exoskeletons for its soldiers to enable them to carry heavy equipment packs and weapons. However, the body must be connected to the exoskeleton at the limbs and other parts by means of straps and other mechanical attachment devices. The exoskeleton's motor must be regulated by various sensors and controls, and driven by hydraulics, pneumatics, springs, or other motorized mechanical systems. These can be cumbersome and expensive systems that do not necessarily reduce the stress on the body caused by gravity.
Athletes and older people suffering from joint injuries have rehabilitated in pools and water tanks. The buoyant property of the water provides an upwardly-directed force to the body that lightens the load otherwise directed to the joints. However, these types of systems are not portable, since the person is confined to the pool or water tank. Moreover, pools or water tanks may be unavailable or expensive to install.
Another approach is provided by a harness system exemplified by U.S. Pat. No. 6,302,828 issued to Martin et al. Consisting of an overhead frame to which is connected a raiseable body harness, such a system supports a portion of a person's body weight as he, e.g., walks or runs on a treadmill in order to diminish downward forces on the body joints. But the straps and attachment devices create localized pressure points and stresses on the body, and restrict the range of motion of the body and its limbs. Such a mechanical weight off-loading system may also lack portability.
The National Aeronautics and Space Administration (“NASA”) has developed a system that utilizes differential air pressure to provide a uniform “lift” to the body to assist the exercise process. See U.S. Pat. No. 5,133,339 issued to Whalen et al. The differential pressure is applied to the lower half of the person's body that is sealed within a fixed chamber to create a force that partially counteracts the gravitational force on the body. A treadmill contained within the sealed chamber allows the person to exercise. However, this Whalen system requires a large, immobile pressure chamber containing a treadmill. Such a system is expensive and requires cumbersome entry and exit by the person. It will not enable the person any other means of exercise besides the treadmill.
Pressurized bodysuits have also been used within the industry for several different applications. For example, U.S. Published Application 2002/0116741 filed by Young discloses a bodysuit with integral supports and internal air bladders that are filled with pressurized air. This air pressure exerts force against the muscles of a person wearing the suit to tone them during daily activities. U.S. Pat. No. 6,460,195 issued to Wang illustrates exercise shorts with buckled belts, air bags, and a vibrator that directs pulses of pressurized air to the body to work off fat and lift the hips. U.S. Pat. No. 3,589,366 issued to Feather teaches exercise pants from which air is evacuated, so that the pants cling to the body of an exerciser to cause sweating, thereby leading to weight loss.
The U.S. military has also employed pressurized suits of various designs for protecting fighter pilots from debilitating external G-forces. Due to rapid changes in speed and direction, the fighter pilot's body undergoes very high accelerations. This normally forces the pilot's oxygen-laden blood away from the portion of the circulatory system between the heart, lungs and brain, pooling instead toward the blood vessels of the lower extremities. As a result, the pilot can lose situational, awareness and spatial orientation. A pilot's bodysuit pressurized against the blood vessels of the legs can force the oxygen-laden blood back to the head and torso of the pilot. See U.S. Pat. No. 2,762,047 issued to Flagg et al.; U.S. Pat. No. 5,537,686 issued to Krutz, Jr. et al.; and U.S. Pat. No. 6,757,916 issued to Mah et al. U.S. Pat. No. 5,997,465 issued to Savage et al. discloses a pants bodysuit made from metal or polymer “memory material” that is heated by electrical current to form around the body, and then cooled to apply pressure for treating this G-forces phenomenon.
Pressurized bodysuits have been used previously for other purposes, such as splinting leg fractures, stopping bleeding from wounds, treating shock, and supporting the posture of partially paralyzed patients. See, e.g., U.S. Pat. No. 3,823,711 issued to Hatton; U.S. Pat. No. 3,823,712 issued to Morel; U.S. Pat. No. 4,039,039 issued to Gottfried; and U.S. Pat. No. 5,478,310 issue to Dyson-Cartwell et al. Bodysuits can also have air between the suit and the body evacuated by vacuum to draw the suit into close contact with the body. See U.S. Pat. No. 4,230,114 issued to Feather; U.S. Pat. No. 4,421,109 issued to Thornton; and U.S. Pat. No. 4,959,047 issued to Tripp, Jr. See also U.S. Published Application 2006/0135889 filed by Egli.
Such pressurized body suits have not previously been used to rehabilitate skeletal joint injuries or minimize conditions that cause erectile dysfunction. Moreover, they have typically been used only in stationary situations like a sitting pilot due to the problem of air pressure forcing the body suit off the lower torso. In some applications like weight-loss patients, suspender straps have been required to overcome this downwards migration of the bodysuit pants.
Thus, a pressurized bodysuit that can be used to apply localized differential pressure to a lower or upper body part for injury rehabilitation or minimization, coupled with an external support or pressure condition control system would be beneficial, particularly due to its portable nature. Such a pressurized body suit system could be worn by a patient, athlete, or other person within a variety of settings to perform a variety of different functions.
Ambulatory assist devices such as walkers, rollators, are used to assist elderly or physically-impaired people undergoing rehabilitation, or people suffering from gait and balance problems due to strokes, Parkinson's and other neurological disorders. These devices are used to provide balance and some measure of body weight support often by the person using their arms and hands. Use of these devices requires the disabled person raise himself from a sitting position to a standing position in order to use the device to ambulate. However, physically impaired people often lack the strength and or balance in order to raise themselves from a sitting to a standing position without assistance. This prevents people from independently using ambulatory assist devices. Also providing personnel for assistance entails additional costs for rehabilitation institutions or in providing home care. Walkers that incorporate a means for assisting a seated person to stand are commercially available or otherwise known in the art. One example is U.S. Pat. No. 7,363,931 which provides lifting arms to assist in standing. One commercially available device is “The New Lift Walker” available from newliftwalker.com. It incorporates a harness and arm supports and a pneumatic lift device to assist in raising a person from a seated to a standing position. These devices generally lack having a body weight support capability. Instead the person is able to provide some body weight support using their arms and hands as supports. Some mobility assist devices utilize a harness to provide body weight support. However harness systems have the drawbacks we have described earlier. There is a need for improved mobility assist devices that provide both improved means of body weight support and a means for assisting a person to raise himself from a seated to a standing position. The wheeled support aid with lift mechanism may utilize electric or pneumatic power sources or both.
Training of gait and balance with body weight support (BWS) is a promising rehabilitation technique. The current body weight support method utilizes an overhead harness support mechanism for which commercial systems are available. One harness system is exemplified by U.S. Pat. No. 6,302,828 issued to Martin et al. Consisting of an overhead frame to which is connected a raiseable body harness, such a system supports a portion of a person's body weight as he, e.g., walks or runs on a treadmill in order to diminish downward forces on the body joints. Harnesses for body weight support attach upper torso and the pulling force on the body is directly upwards. This restricts the natural position of the body during running and walking to a forward leaning position. Because harness systems pull the upper body directly upwards from the chest they are can provide too much stability for balance training. Another issue with the harness based body weight support is that the harness supporting the subject decreases the need for natural associated postural adjustments (APAs) that are required for independent gait. The main site for an active control of balance during gait is the step-to step mediolateral placement of the foot. When supported by a harness during BWS training any mediolateral movement is restricted by a medially directed reaction force component that will help stabilize the body in the frontal plane and decrease or even eliminate the need for APAs making gait and balance training less effective. Further the straps and attachment devices create localized pressure points and stresses on the body, and restrict the range of motion of the body and its limbs. In particular the straps around the thighs and groin interfere with the back and forth rotation of the legs.
An new alternative to a harness based body weight support is a close fitting differential pressure suit is described in this application and in U.S. Patent Application [US 2010/0000547, PCT/US2009/003535, EP 09762926.5]. A differential pressure body suit with external support against body suit migration is provided by the invention. In its preferred embodiment, such body suit may comprise a close-fitting, multi-layered suit sealed against a person's skin to contain the differential pressure, or a looser-fitting space suit that bends at the joints with minimal force. External support means include either fixed or movable mechanical supports attached to the body suit, extraordinary air pressure levels for making the body suit rigid, or exoskeletons attached to the body suit. This differential pressure body suit provides a portable and convenient system for rehabilitating a skeletal joint injury or training for injury prevention or athletic performance. The pressurization reduces the weight of the body to greater or lesser extents, and offloads the weight to the ground through the external support means. The body suit is flexible and has joints that can flex with minimal force even under pressure.
In either harness based approaches or partial pressure differential pressure suit means are required for attaching the harness, pressure suit or other attaching means to the mechanism that provides the counter-force body weight support. Harness systems use ropes straps and or cables to attach the harness system to the overhead counter-weight system. A natural walking or running gait consists of body movements or rotations about various axes of the body. It is important that the connecting system not unduly restrict these movements. There is a need for body weight support systems that do not restrict natural body movements.